Conventionally, property modification of a surface of a substrate consisting of glass, metal, plastic or ceramics, is performed in various field, according to its purpose. For example, a method comprising coating a fluorine-containing silane coupling agent, in order to confer water repellency and oil repellency to the surface of glass or plastics can be exemplified.
As a method for forming a coating film to improve a substrate surface, for example, Patent References 1 to 3 disclose a method for producing a chemisorbed film, which has high peel resistance and high transparence, and which gloss of the substrate surface and transparency of the substrate are not lost. However, the methods for producing a chemisorbed film described in these references comprise forming a coating by a dehydrochloric acid reaction of a chlorosilane surfactant and an active hydrogen of the substrate surface, which had drawbacks of generating a harmful chlorine gas when producing the film.
A method for forming a chemisorbed film by a dealcohol reaction of alkoxysilane surfactant is also known. However, this method had drawbacks that the reaction velocity of dealcohol reaction is slow and that the film forming was not easy to conduct.
Further, a method of promoting dealcohol reaction by using a dealcohol catalyst is proposed, while by merely adding a dealcohol catalyst, the surfactant will cross-link by itself due to the moisture in the air, thereby inhibiting the reaction in the solid-liquid interface of the substrate surface, and it was difficult to form a monomolecular chemisorbed film with good efficiency.
In order to resolve these problems, in Patent Reference 4 is proposed a method for forming a chemisorbed film covalently-bond via a siloxane-bond, by allowing the substrate surface to contact with a mixed solution containing at least an alkoxysilane surfactant, a non-aqueous solvent not containing active hydrogen, and a silanol condensation catalyst. As a silanol condensation catalyst, at least one substance selected from metal carboxylate, metal carboxylate ester, metal carboxylate polymer, metal chelate carboxylate, titanate ester, and titanate ester chelate, is exemplified.
Further, as a method for forming a chemisorbed film having crystalline property on a substrate surface, a method of forming a crystalline monomolecular film comprising developing an organic solvent solution of silane surfactant on a silicone wafer surface where purified water has been dropped, is disclosed in non-patent reference 1.
Further, in Patent Documents 5 and 6, it is known a method for fixing a water-repellant coating film consisting of monomolecular layer, to a substrate surface via a silanol group, by using a monomer or polymer of a hydrolysate of fluoroalkyl group-containing silane compound which has been hydrolysed in the presence of an acid catalyst.
However, this method requires a long time for film forming, and it had drawbacks such that when film forming is conducted while silanol condensation catalysts, etc, are remained in the solution, these catalysts inhibit the adsorption, and a dense monomolecular film could not be formed. Further, in these methods, the types of substrates which can be used are limited, and a crystalline chemisorbed film could not be formed on a non-crystalline substrate.
Therefore, particularly in the field of fine patterning in the design of electric devices, the development of a technology for quickly forming a dense monomolecular film with less impurity was awaited.
Thus, the present inventors developed a method for reducing the film forming time, by using a solution for forming an organic thin film which moisture content has been adjusted or kept to be 50 to 1000 ppm, when allowing the substrate to contact with an organic solvent solution obtained by mixing a metal surfactant having a hydrolysable group and a catalyst that can interact with the metal surfactant, or with the solution for forming an organic thin film obtained from the organic solvent solution and the metal surfactant having a hydrolysable group (Patent Document 7).
However, with this method, as catalysts tend to precipitate, etc. due to the high catalyst concentration, the solution for forming an organic thin film cannot be stored for a long time. Further, this method requires a long time for preparing an organic thin film since it cannot be carried out with a low amount of water.    Patent Document 1: Japanese Laid-Open Patent Application No. 4-132637    Patent Document 2: Japanese Laid-Open Patent Application No. 4-221630    Patent Document 3: Japanese Laid-Open Patent Application No. 4-367721    Patent Document 4: Japanese Laid-Open Patent Application No. 8-337654    Patent Document 5: Japanese Laid-Open Patent Application No. 11-228942    Patent Document 6: Japanese Laid-Open Patent Application No. 11-322368    Patent Document 7: WO2006/009202    Non-Patent Document 1: Bull. Chem. Soc. Jpn., 74, 1397-1401